Hmn... I guess I am one who could give you some pointers, as I am from Rio, but am living in Honolulu right now for some months.
Weather
Think Honolulu think SUNSHINE. It is sunny as ever here, few clouds and it never gets completely cloudy days. It doesn't seem to rain much as well, only small bursts that go away fast. In contrast, Rio rains a lot, especially during summer months, even known for serious flooding in some neighbourhoods. Rio is also much hotter than Honolulu. I am no good with Farenheit, but in Celsius, I'd say that Honolulu doesn't get over 32C, whereas Rio during summertime is known for its rising temperature possibly over 40C (there is a popular song named after that: "
Rio 40 Graus"). I would be pleased if summer in Rio felt like it is here...
Cost of living
Even though Dollar is worthed more than the Real, I think I'm actually quite confortable here in Honolulu, budget wise, compared to if I was in Rio. I am a person of simple taste and don't spend much, but for what I've been doing here, back home I'd be spending much more. Cost of living in Rio is HIGH. Food there is expensive, gym is expensive, night outs are insanely expensive. Comparatively, I'm spending less here. Let's say an average night out here for me goes as 30 dollars, whereas in Rio it would be 50-60. Gym over here costs me 50 dollars, as over there it would be possibly something closer to 100 dollars... crazy.
Food
Well, my main concern with food is eating healthy and following my low carb, high protein diet. I am actually happy to find out you can eat really well for a good price here. I just eat a ton of fish with veggies and brown rice. You can eat healthy in Rio too, but it is definetely more expensive. I'd suggest you cook in Rio. In terms of quality, I'd say both places have good, tasty food overall. If you are into japanese food, both places have planty of options.
City life
One of the things that I felt most contrating was city size: Honolulu feels like a small city. It made me realise how big Rio is. Honolulu
feels small for me. Here, I feel confortable simply walking my way all over, as in Rio, I'd be getting the subway or buses for everything. Even then, I find that proportionally Honolulu has more homeless people than Rio... I was somewhat surprised to see that.
If you are into drugs (not my thing) I am sure that in both places you'd have easy, easy access to it. But my brazilian acquaintances over here tell me that weed in Rio is -merda- compared to here.
Honolulu is much more chill than Rio. I find that Rio is INTENSE whereas Honolulu is more laid back. People here are mellow and friendly. Not saying that people in Rio are unfriendly, but are definetely more paranoid and can hold it back a bit more. You must consider that it is a big city with a violent past, and those marks linger on. Cariocas can be very intense people, for better or worse.
Honolulu is safe. I find it 100% safe and walk around all over day and night without a single worry. Rio, I personally have no worries as well (my overall atittude), but that might be different for foreigners. Yet, I don't think crime or violence issues should put anyone off Rio. Things are getting safer there, you just gotta be smart (as it is a big city) and inform yourself about some places you should avoid.
Honolulu is much more international than Rio. Prior to coming here, I've never met people from Vietnam, Cambodia, Phillipines or South Korea. Not many young asians travelling to Rio, which is a damn shame, for I love asian culture and women. Rio has plenty of Europeans, North Americans and Aussies/Kiwis.
Nightlife
The nightlife in Rio has been changing A LOT, but overall, it has plenty and growing options that suddenly sprawl, as many new places are popping up. I'd say that venue selection plays big in Rio, and it is important to find your niche and stick to it. Rio has many options between Thurs-Sun, but is quiet during the other days. Weekends can be very VERY full in some venues, maybe even unbearable. Best things about Rio's nightlife compared to here is that there you don't get all these boring US regulations you have here. You can dance with your drinks in the dancefloor, party usually really starts at midnight and ends at 6-7, and there are plenty of nice places to pre-drink and meet people. You can drink on the streets at will, and piss also may I add, with no police bothering you. These are the things I miss the most over here and the main things that put me off this place. Plenty has been said about Rio's nightlife in other threads.
In Honolulu there seems to be a bit less options and it took me some time to figure the places to go. I am still exploring, but I am guaranteed to have decent and full (and budget friendly) places to go at least 4 times a week. At waikiki during the week, there is always a place or other that on a specific weeknight has a "one-dollar drink" night, where people flock. By "people" I'd say 75% foreigners or tourists, as these seem to be more of the crowd that hit the places I've been to at Waikiki. Downtown Honolulu has nice bars and a few clubs (Soho, Aloha Tower venues) that more locals flock. I'd prefer downtown, if not for the parties ending earlier than those at Waikiki (Waikiki parties end at 4am, downtown at 2am). The venues here always seem to have a nice number of people. I've never been to a crowdy venue here, wheres in Rio I was avoiding going out on Saturdays because of this. I find the drinks here in Honolulu considerably better than Rio's. Brazilians drink BEER, they will only have taste and demand for good BEER. Grey goose?? Jack Daniels?? Forget it, you will rarely find those in Rio (in most $average$ venues), and if you do, NO LESS than 10-15 dollars for it. Here, Jack and Cola = 5 dollars, in Rio (IF you find it) 20 reais.
Women
Local girls or Asian immigrants, ie: girls that don’t usually hang out with the huge foreigner crowd, seem to be out of this world for me. I have a much easier time relating to the Europeans (TONS of German and Scandinavian girls here) or mainland American, although most of these aren’t really my preference. I find it hard to find anything that works consistently with the girls here, as my Brazilian game (hey, I’m no caveman, but I am used to working my way with Brazilian girls) seems to be less effective over here. I am used to things moving faster, and the pace here is very different. I actually had a cool Brazilian guy who’s been living here for over a year tell me “Dude, if you want sex, go to Brazil, here you have to relax.” Meaning that I was used to one kind of game that worked in Brazil, but here it just doesn’t seem to bite. The drill here is different. Whereas I was on a pretty good streak back home prior to my departure (I was learning how to
juggle girls, haven’t caused more damage solely due to lack of time), here I turned into a phone collector (girls really give their numbers like candy, whereas in Brazil it is more common for a girl to make out with you but not necessarily give her number. Brazilian girls are easy kissers, but that doesn’t guarantee the bang.)
I’ve had few successes here, with a drunk Chinese-american girl from Pasadena (ironically the fastest makeout in my life. 10 min after entering the venue, I was making out with her and she had her hand on my cock) and a chubby girl from Argentina. I had tons of phone numbers that ended nowhere. I am sure that for the amount of work I’ve done here, I’d be much better back home. I actually find that good, as my learning curve is going up incredibly, and I am learning to be much more relaxed and confident with the collected experience.
Summing up, I’d say that girl-wise you’d have to know what you are after. I have a kink for Asian girls, as tough they seem to be to crack (there are gazillions of Japanese tourist girls over here, and although they are on vacations, they just don’t seem to be readily open for random cock, or so it seems in my experience). Brazilian girls might be easier, and they do value more direct/alpha game overall. See what kinda girl/ game suits you. Think Honolulu : Asian/Pacific girls with quite a bit of German/Scandinavian tourist girls on the more foreigner-oriented venues. Rio: Brazilian girls of all shape and sizes, which are quite a treat themselves.
Hope to have been of some help.